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[oletrucks] How to set up a TPI smallblock

To: oletrucks@autox.team.net
Subject: [oletrucks] How to set up a TPI smallblock
From: MarkNoakes@aol.com
Date: Sat, 6 May 2000 18:24:41 EDT
With the commentary on the 400 vs 350 TPI, I edited some info that was 
published on the SCCA Solo2 (autocross) BSP (class B, street/prepared) list.  
The car that this engine was in ran at the Dogwood Grand Prix this year 
(fastest Solo2 event in the country and only one on city streets I know of).  
It took second out of 100 cars entered; first was also a Corvette with a 
later engine. . .didn't beat him by much though.  

The SCCA SP class doesn't permit nonstock head/cam swaps. . .mostly just 
tuning, balancing, etc.  He put alot of time into the car but not parts 
dollars so this could be considered an alternate approach to building a 350 
TPI motor.  This car as modified below was very fast but of course I don't 
have hp numbers.  I hope to follow this guy's example with many of his mods 
this year.

And even with the mods listed, it also passes emissions tests. . .interesting.

I cut out all of the suspension mod stuff as irrelevant for the old trucks 
but it was just as interesting to me!!!. . . .

Mark Noakes
58/56 Suburban
66 Corvair Monza turbo
86 Silverado short bed
86 Corvette Indy convertible, SCCA BSP #32
Knoxville, TN



I decided to take a conservative approach. I know the L98 has killer low
& midrange torque in stock form. So, I just balanced the 90 engine when I
built it. Then I did a bunch of die grinding on the intake and exhaust
manifolds just to clean it up so it would flow a little better.
Specifically, I rounded out any corners and rough areas and totally
ground down the "dams" behind the throttle body since I disabled the EGR
system. I also matched the upper plenum openings to the runners that go
down to the lower manifold. On the lower manifold, I just made sure the
air would make a smooth turn from the runners to the heads.

The exhaust manifolds had some really gross AIR tubes protruding into
them. So, I ground them down and smoothed up the welds in the collector
area. I also "knife edged" the collector cross piece and rounded the edge
of the cone shaped collector transition. I capped the AIR tube on the
upper end. I had the EGR tube welded up on the passenger side manifold.

I got an 84 front Y pipe and gutted catalytic converter (plugged the AIR
tube). Then bought a new 85 rear Y pipe and connected up my Borla

Transmission -

Stock 700R4 as per Solo II rules (rebuilt last year). However, they allow
any torque converter, so I bought an Art Carr 2400 stall lock-up
converter (thanks for the tip Ken Mitchell!). I have the 3.07 rear gears
so my theory is that with the stock intake and stock free-flowing exhaust
that the converter would put the motor right in it's sweet spot.

Performance - 

With only 650 miles on the motor the acceleration was VERY strong. It
corners very flat and is dead neutral handling. I can use the throttle to
set the car where-ever I want on the course.
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

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